Bichard dijkstea



R DIJKSTRA. THERMAL cmcun CLOSER. I APPLICATION FILED NOV. 9. IQIS.1,307,086, Patented June 17, 1919.

RICHARD DIJ'KSTR A, OF CHICAGO, ILLINOIS.

THERMAL CIRCUIT-CLOSER.

Specification of Letters Patent. 'Patente (1 June 17 1919.

Application filed November 9, 1918. Serial No. 261,887.

I T all whom it may concern:

- ers,

Be itknown that I, RICHARD DIJKSTRA, a citizen of Holland, residing atCicero, Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Thermal Circuit-Closofwhich the following is a. specification,"reference being had to theaccompanying drawings.

This invention relates to thermostatic alarms, and particularly to thatclass of alarms wherein the rise or fall of mercury Within the bulb of athermometer causes the sounding of an alarm.

The general object of my invention is to provide a very simplethermostatic circuitcloser for electrical alarms designed to providemeans for warning gardeners, farmers, and fruit growers of changes intemperature which might become dangerous, so that they may take thestepsnecessary to save their crops. A further object is to provide athermostatic alarm adapted to be used in connection with an electricsignal so constructed that it may be adjusted to sound the alarm atdifferent temperatures or to be rendered entirely inoperative as regardssounding an alarm at the will of the operator. Other objects will appearin the course of the following description:

Figure 1 is a face view of a thermostatic alarm constructed inaccordance with my invention;

Fig. 2 is a fragmentary, vertical section of the thermometer tube andallied parts; and

Fig. 3 is a transverse section thereof.

Fig. 4 is a cross section of the float 12.

Referring to the drawings, 10 designates a thermometer tube of anysuitable material, as for instance of glass mounted upon a suitablesupporting base 11, the tube 10 being about five times the size of theordinary thermometer tube, and being provided with the usual bulb at itslower end, and containing mercury. Disposed within the tube is a float12 which may be made of any suitable material, and carries an upwardlyextending rod 13, which is preferably tubular, this rod at its upper endcarrying two oppositely disposed outwardly bowed spring leaves 14.

Disposed at intervals through the tube of the thermometer in spacedrelation to each otherare pairs of contacts 15, which are preferably ofcopper. These contacts have rounded inner faces which project into thepath of movement of the springs 14: and are adapted to be engaged by thesprings as the float rises or falls. The springs 11 are electricallyconnected to each other and when the springs are in contact with thecontacts 15 they electrically connect the contacts of a palr.

' Disposed in spaced relation to the contacts 15 and extending parallelto the two lines of contacts are the copper strips or wires 16 which arefastened to the base 11 by screws or other suitable means, these screwsat one end being binding screws for engagement by wires 17 which extendto a source of energy andto the bell or other alarm. The contacts 15 arespaced from the strips 16 and the base 11 is formedwith a plurality ofsockets or recesses 18, the wall of each socket at one end being formedby a contact member 15 and at the other end by the strip 16. In order tobridge this recess or socket and electrically connect the contacts of apair with the strips 16, I provide a connector 19., which is formed ofwood, fabric or other insulating material having a handle and providedupon one face with the plugs 20 of.

copper or other electrically conductive material. These plugs areadapted to fit within the sockets 18 and to electrically engage thestrip 16 with its adjacent contact 15. The wires 17 may connect with anysuitable source of current and bell or other electrically actuatedsignal.

The operation of this mechanism will be obvious. vWhen the exteriortemperature is at 32 degrees Fahrenheit for instance, the float 12 willmove to this point and at this time the contact springs 14 will bedisposed between the lowermost contacts 15. It now the plugs 20 of theconnector 19 have been disposed in the sockets associated with thislowermost pair of contacts, it will be obvious that upon the descent ofthe springs 14 to this point, a circuit through the signal and batterywill be completed and the bell will ring or any other signal will begiven. The uppermost pair of contacts may correspond for inst-ance, to atemperature of 44 degrees Fahrenheit, and in this case the bell willring when the exterior temperature has risen to 1 1 degrees. While Ihave shown four 1 caused to sound, or when the temperature falls to acertain point, the signal may be actuated,or by the use of twoconnectors 19 the bell may be actuated upon either a rise or fall oftemperature beyond or below certain degrees. 3-

It will be seen that device is very simple, it may be easily used andapplied, and that it cannot readily get out of order. It is obvious alsothat it may be modifiedin many ways without departing from the spirit ofthe invention. Thus, while I have shown a thermometer tube 10 which isD- shaped in cross section, I do not wish to be limited to this, as anyform which is many sided in cross section may be used. The purpose ofmaking the tube D-s'haped in cross section-and the float to conformthereto is to preventany rotation of the float and therefore keepthe'contacts 14 the contacts 15. Preferably the float 12 will have theform illustrated in Fig. 4, that is,

the float will be annular and the rod 13 will be tubular, and there willbe perforations or other openings at the upper rod 13 which will permitthe mercury to pass up through the float and into the rod where there isa very high temperature which the upper end of the rod to the top end ofthe tube. likelihood of the 10 when the thermometer is submitted to ahigh temperature.

hat is claimed is:

1. A circuit-closing thermostat including a thermometer, a float movabletherethrough by the rise and fall of liquid Within the would cause abutagainst This prevents any thermometer and having a stem smaller in theinterior diameter of the diameter than I thermometer tube and carryingopposed conin line with spring contacts,

mercury bursting the tube nected contacts, a series of pairs of contactsextending through the wall of the tube and disposed in the path ofmovement of the first named contacts, conductors disposed on each sideof the thermometer and extending parallel to the contacts on that sidebut spaced therefrom, and a connector having means for bridging thespace between any pair of contacts and the corresponding conductors, theconductors being adapted to be connected in a circuit with a signal anda source of energy.

A circuit-closing thermostat comprising a base, a thermometer mountedupon the base, a floatv riding upon the mercury in the thermometer andcarrying an upwardly extending rod, oppositely disposed outwardly bowedsprings carried upon the rod, a plurality of oppositely disposed pairsof contacts extending through the wall of the thermometer and spacedfrom each other and disposed in the path of movement of the a pair ofconductors disposed on opposite sides of the thermometer and spaced fromthe contacts, a space between each contact and the correspondingconductor forming a socket, and a connector comprising an insulatingbody having a handle and two plugs adapted to fill such sockets andelectrically connect a pair of contacts with the correspondingconductors, the conductors being adapted to be connected with a sourceof energy and the signal.

In testimony whereof I hereunto. aflix my signature in the presence oftwo witnesses.

RICHARD DIJKSTRA.

